| | 1. Upper surface leaf blade midrib glabrous, blade ± membranous to leathery, not fleshy |
| |
| | 2. Leaf segment generally < 2.5 cm, generally < 1 cm wide; leaf blade ± membranous to ± thick, not leathery, ± firm, not brittle; sori round to ovate, 1–3 mm |
| P. hesperium |
| | 2' Leaf segment 2.5–7(10) cm, 0.9–1.8(2.5) cm wide; leaf blade thick, leathery, firm, brittle; sori ovate to round, 2–6 mm |
| P. scouleri |
| | 1' Upper surface leaf blade midrib hairy, if glabrous, blade membranous to fleshy, not leathery, often firm |
| |
| | 3. Veins free; sori generally round |
| P. glycyrrhiza |
| | 3' Veins free and fused; sori generally ovate |
| |
| | 4. Leaf blade deltate to ovate, often ± irregular in outline, lower 1–3 segment pairs often = or > those above; sori ± sunken, ± flat, round to generally ovate; North Coast, Central Coast, Outer South Coast Ranges, Southwestern California (except perhaps San Jacinto Mountains) |
| P. californicum |
| | 4' Leaf blade oblong-ovate, ± regular in outline, lower 1–3 segment pairs generally < those above; sori raised, ovate; Northwestern California (except High North Coast Ranges), Cascade Range Foothills, Sierra Nevada (except s Sierra Nevada Foothills), Sacramento Valley, Central Western California |
| P. calirhiza
|